The present invention relates generally to coupling of structural components to form an overall structure and system. More particularly, the present invention relates to clamping arrangements coupling together structural components to form, for example, playground structures.
A playground structure depends from a set of vertically disposed frame components, e.g., five-inch diameter steel or aluminum-alloy posts, secured by ground-footings in vertical orientation and at selected positions according to a planned structure layout. Additional structural components then mount to and between such vertical posts to complete the playground structure plan. The subject matter of the present invention allows attachment of such additional playground structural components each at selected vertical position and radial orientation relative to such vertical posts.
U.S. Pat. No. 5,785,447 issued Jul. 28, 1998 to Fonti et al entitled xe2x80x9cConnector For Structural Apparatusxe2x80x9d shows a connector including a pair of hemi-annular clamps joined together at abutting ends thereof to capture therebetween a vertical post. The resulting annular clamp presents upper and lower annular ridge formations in offset concentric relation to the post. A component-mounting element slidably positionable about the annular clamp structure engages the upper and lower ridge formations and supports a component extending radially outward therefrom. In one embodiment, the component mounting element is bifurcated into upper and lower parts engaging the upper and lower annular ridges from above and below, respectively.
U.S. Pat. No. 5,575,580 issued Nov. 19, 1996 to Parish et al and entitled xe2x80x9cConnector For Structural Apparatusxe2x80x9d shows a disclosure similar to that of U.S. Pat. No. 5,785,447 as discussed above.
Unfortunately, the slidable relationship between the component-mounting element and the annular clamp, while establishing non-discrete or analog positioning of the component-mounting element relative to the annular clamp, minimizes the contact surface area of the interface therebetween. This maximizes the component load force per surface area by focusing load forces on the minimal contact area.
As may be appreciated, components in a playground structure must mount securely without risk of loosening or of detachment and resulting structural weakness or failure. The stronger and more reliable the coupling between the vertical posts and components attached thereto the better the overall playground structure. Furthermore, due to the modular design approach taken in most playground structure plans, such clamping arrangements should possess an ability to support versatile clamping patterns including variation in vertical height as well as radial orientation relative to the vertical posts. Finally, to minimize manufacturing costs, such clamping arrangements should provide the greatest degree of versatility with the least number of clamping device types.
The subject matter of the present invention provides such a clamping arrangement particularly well-suited for playground structures and particularly versatile in clamping arrangements as to height and radial orientation as well as broad variety in the type of components attachable in secure fashion to the vertical posts of a playground structure.
Generally, the present invention departs from the minimal surface contact area as provided by the circular, i.e., concentric to the post, contact surface engagement geometry of the prior art by use of discontinuous or non-concentric contact surface engagement in such orientation and pattern to lock together upon engagement the collar-clamp and the associated mounting component assembly.
As in prior art systems, structural components depend from cylindrical posts and annular clamps concentric to and engaging the posts at a selected position therealong and at selected radial orientation thereabout carry thereon component-coupling members. The annular clamps under the present invention, however, include a first contact surface non-concentric relative to the post but following an annular path concentric to post. As in the prior art, the component-coupling member attaches to and supports the component. The component-coupling member under the present invention, however, includes a second contact surface matingly compatible to inter-fit the first contact surface. The second contact surface engages the first contact surface to transfer from the second contact surface to the first contact surface a load force originating from the component.
The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation of the invention, together with further advantages and objects thereof, may be understood best by reference to the following description taken with the accompanying drawings wherein like reference characters refer to like elements.